DANBURY -- Columbine High School Principal Frank DeAngelis never thought his suburban community would be in headlines and on TV news segments relating to shootings. Then, on April 20, 1999, he found himself in a hallway wondering what it was going to feel like to be shot as two gunmen fired weapons in the school for 45 minutes.

"Every time someone said to me, 'I know what you're going through,' I'd try to be polite, but said, 'You have no clue what I went through. You did not walk over dead bodies. You did not see shots fired your way, so don't tell me,'" DeAngelis said Wednesday night in an emotional and blunt description of the mass shooting at his Colorado school and the struggle to move forward. "They just don't know what to say."

DeAngelis and three others with experience in recovering after violence spoke in a panel discussion and community forum at Western Connecticut State University called "Recovery and Resilience after the Sandy Hook Tragedy." The gathering, sponsored by the university and United Way of Western Connecticut, gave panelists a chance to offer advice on dealing with the aftermath of the Dec. 14 Sandy Hook Elementary School shootings that left 20 children and six adults dead. The gunman, who killed his mother in her Newtown home before heading to the school, also killed himself as police closed in.

DeAngelis admitted to shutting out his family after the Columbine shootings, hoping to avoid conversation of it when he got home from 60- to 70-hour work weeks. The shooting also led to him being named in eight lawsuits and suffering from post-traumatic stress disorder.

He also watched it affect those at Columbine High School, saying, "We could not serve Chinese food ... because that was what was served the day of the shooting. We could not put ketchup out."

Members of Columbine's class of 1999 and their spouses still call DeAngelis for help because the shooting has continued to impact their lives. He emphasized the importance of asking for help and seeking counseling, and recommended Newtown maintain support for those affected by the slayings for years to come.

Mary Fetchet, whose oldest son died in the Sept. 11, 2001, terrorist attacks while working in a World Trade Center tower, recalled that she was "still in shock" for about a year after that. The social worker co-founded VOICES of September 11th as a way to connect and provide support for families who lost loved ones, rescue workers and survivors, and to spread awareness of terrorism and the importance of preparedness and response.

She said planes flying overhead, fire alarms and the shift from summer to fall are "triggers" that can upset those affected by Sept. 11, and that her family found ways to get through their grief that became new rituals.

"You have to figure out how are you going to celebrate birthdays, how are you going to celebrate holidays, how are you going to celebrate the first anniversary," Fetchet said.

Jamie Howard, a clinical psychologist and director of the Stress and Resilience Program at the Child Mind Institute, explained how to recognize and address traumatic stress, particularly in children, and has been working with a Sandy Hook student.

The little girl has drawn pictures as a therapeutic activity, and explained she was behind a locked door during the Newtown shooting, which made her feel safe. But she kept drawing pictures of her teacher, who was killed.

"She thought there might be guns in Heaven, and that is what was making her so sad," Howard said, adding that the youngster needed reassurance there are no guns in Heaven.

Greg Young, a chaplain who responded to the August 2012 Sikh Temple shooting in Wisconsin, noted that trauma will affect everyone in different ways.

"It impacts you in so many ways over a long time," Young said. "Know most of those reactions are normal reactions to horrible, abnormal events."